Unlike common milkweed (Asclepias syriaca) and several other milkweed species, this one does not spread by underground rhizomes. It is short and stays in a neat clump, which gets bigger every year. It's a good choice for small yards or formal gardens.

The root is a thick taproot, not a tuber as the species name tuberosa would suggest. In the case of this species, the Latin word tuberosa means "having swellings" and refers to bulges that sometimes develop on the taproot.

It certainly does have a thick taproot. When I was a kid I went out with my father to dig some up by the side of a back road and getting that taproot in one piece was really a challenge. So was the poison ivy! In the wild it seems like if you see this butterfly weed, you need to pay attention for poison ivy, too.